S14 SR20DET TROUBLESHOOTING
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sik.infinity
- Posts: 2
- Joined: Fri Sep 21, 2007 12:00 pm
S14 SR20DET TROUBLESHOOTING
ZENKI S14 WITH ZENKI SR. WIRING DONE BY WIRING SPECIALTIES. SO JUST GOT THE CAR STARTED UP AND RAN FINE FOR LIKE 20-30 MIN THEN ALL OF A SUDDEN NO.3 CYLINDER STOP FIRING,SOUNDED LIKE WRX, CHECKED IGNITOR, CHECKED WIRES TO IGNITOR CHECKED INJECTORS NONE OF THOSE IS THE POROBLEM. SPARK PLUGS OLD BUT WAS WORKING AND WORKS IN CYL.2 WHAT COULD BE THE PROBLEM. TIMING?ECU?IGNITOR CHIP? ANYONE GOT IDEAS?
FuelSparkCompression
Take one of these away and you will have a miss.
It MUST be one of the three.
I would think NOT timing, ecu, or ignitor if it is only 1 of the 4 cylinders missing.
Test fuel pulsewidth signal, by using a 12v LED in the injector connector lead while cranking/running.
If you do not have a signal, test for supply power on the connector in "key on" position, then test continuity to ground between the connector and the ECU.
-------------------------------------------------------------
Test fuel injector by listening for an audible or physically feeling the "click" of the injector opening and closing. You can use another injector connector and lead to make a test lead utilizing battery voltage to cycle the injector on/off to test its functionality.
BAD: Replace injector.Good: Questionable if injector is simply clogged or not, but less likely.
--------------------------------------------------------Remove coil packs, using a test spark plug, insert into coil pack, ground and crank engine. Check for spark on plug.
No Spark:Test supply power to coils=eccs relay and supply voltage good/bad (should be the same as battery)Test 12v return to 4 pin connector on ignitor=testing coil returnTest continuity of 5 pin connector to ecu ground/ignition input=Good/bad signalTest E wire for groundcontinuity on coil.= good/bad groundTest 5 pin connector for 12v on 1-4: 12v=goodcoil
-----------------------------------------------------------Replace plugs while doing this test, it may be one of the plugs.Plugs=Good Bad---------------------------------------------------------Perform compression test while replacing plugs, analyze results
Cold compression over 130 should yeild a non miss situation at idle.-----------------------------------------------------
If you follow this process for a single cylinder miss, you will track down your problem.
Take one of these away and you will have a miss.
It MUST be one of the three.
I would think NOT timing, ecu, or ignitor if it is only 1 of the 4 cylinders missing.
Test fuel pulsewidth signal, by using a 12v LED in the injector connector lead while cranking/running.
If you do not have a signal, test for supply power on the connector in "key on" position, then test continuity to ground between the connector and the ECU.
-------------------------------------------------------------
Test fuel injector by listening for an audible or physically feeling the "click" of the injector opening and closing. You can use another injector connector and lead to make a test lead utilizing battery voltage to cycle the injector on/off to test its functionality.
BAD: Replace injector.Good: Questionable if injector is simply clogged or not, but less likely.
--------------------------------------------------------Remove coil packs, using a test spark plug, insert into coil pack, ground and crank engine. Check for spark on plug.
No Spark:Test supply power to coils=eccs relay and supply voltage good/bad (should be the same as battery)Test 12v return to 4 pin connector on ignitor=testing coil returnTest continuity of 5 pin connector to ecu ground/ignition input=Good/bad signalTest E wire for groundcontinuity on coil.= good/bad groundTest 5 pin connector for 12v on 1-4: 12v=goodcoil
-----------------------------------------------------------Replace plugs while doing this test, it may be one of the plugs.Plugs=Good Bad---------------------------------------------------------Perform compression test while replacing plugs, analyze results
Cold compression over 130 should yeild a non miss situation at idle.-----------------------------------------------------
If you follow this process for a single cylinder miss, you will track down your problem.